Tony is holding the plate out the window then grabs the girl with that hand without putting the plate down. In addition, the plate has disappeared from the scene.
Tony pays the artist $6,500 by pulling out a few bills counting them in a half hazard manner and handing them over. The largest denomination bill in circulation is the hundred dollar bill, nothing larger is in use. $6,500 would require 65 bills, not something that can be counted in a few seconds, and the stack of bills would be much larger than he handed the artist.